Presentations for Biology Topic 3 Flashcards
Adaptations of the lungs?
high sa to V ratio = lungs have alveoli
alveolus has highly folded
Short diffusion pathway due to the one cell thick of the alveolar wall
Increased blood flow helps to maintain the concentration gradient
Increased ventilation which also helps to maintain the concentration gradient
Mechanics of the lungs work in what way? Inhalation
External intercostal muscles contract and vice versa
ribs up and out = thorax volume increases
Diaphragm contracts = flatten = volume fo the thorax increases
Increase in volume of thorax reduces the pressure in lungs
Atmospheric pressure is greater than pulmomnary pressure = air forced into the lungs
Mechanics of the lungs work in what way? Exhalation
Internal intercostal muscles contract and vice versa
ribs = down and in = decreased volume of the thorax
Diaphragm muscles relax = volume of the thorax decreases
Volume of the thorax decreases = increase pressure in the lungs
Pulmonary pressure is greater than the atmospheric pressure = air goes out
Units for Pulmonary Ventilation?
dm cubed min^-1
What is the formula for pulmonary ventilation ?
Pulmonary Ventilation = tidal volume x breathing rate
Why is the diffusion of gases between the alveoli and the blood very rapid?
The RBCs are slowed through the pulmonary capillaries so there is more time for diffusion
RBCs are flattened against the alveolar walls = distance between the blood and the air is reduced
Alveoli + pulmonary Capillaries have a high SA:V ratio
Constant Ventilation + Good circulation of blood = maintainenance of a good concentration gradient
What is an obviously key point needed for efficient gas exchange in any living organism?
There needs to be a selectively permeable membrane which enables substances to pass into and out of the cell membrane
What is the first major part of the Digestive system ?
Oesophagus = Carries the food from the mouth to the stomach
In chronological order after the Oesophagus are the other major parts of the Digestive system?
2) Stomach that stores and digests food in paricularly proteins, it contains the glands for the digestion of proteins which includes of tripsin and pepsin
3) ileum = upper part of the small intestine which contains villi which give them a large SA which helps with the absorpion of the digested products via active transport and the diffusiom.
4) Large intestine = absorption of water from the glands
5) Rectum i sthe last part of the large intestine in which the faeces is tored before going to the anus to release it via egestion
What is the role of the salivary glands?
They contains the enzyme amylase which helps to digest maltose and other carbohydrates.
What is the role of the pancreas?
It contains all the enzymes needed for digestion of carbohydrates, lipids and proteins ; lipase amylase and the types of protease
How can digestion be split into?
Physical breakdown and chemical digestion
Describe the general break down of the carbohydrate with the enzyme of amylase?
1) Amylase is produced in the mouth and pancreas.
2) Amylse hydrolyses the alternate glycosidic bonds of the starch molecule = dissaccharide maltose.
3) Maltose is then hydrolysed by another enzyme called maltase ino its monosaccharide format of alpha glucose.
Where is maltase produced?
Maltase is produced within the lining of the cell walls of the ileum in the small intestine.
How in steps does the detailed process of the breakdown of maltose?
1) Saliva from mouth is produced and is mixed with the churned food from chewing.
2) The salovary gland then has the amylase which starts to hydrolyse the starch into maltose. PS it contains mineral ions which produce a pH of 7 which is the optimum pH for the digestion of Amylase to occur whithin.
3) Food is swallowed and then the acidic enzymes denature the structure of the enzyme which prevents any further hydrolysis of the starch.
4) While the food reaches the small intetine it mixes with pancreatic juice.
5) The instestinal wall and the pancreas both produce juice that has a pH of 7 which enables the pancreatic amylase in the pancreatic juice to break don any further stacrhc molecules.
6) Occurence of peristalsis lead to the intestinal wall producing the disaccharide maltase which is not released into the ileum but into the cell membranes (Membrane bound maltase). This leads to the maltase hydrolysing the maltose into its monosaccharides of alpha - glucose.
